I tried the logic of php but i am not successfull. how can i make facebook video downloader website? please someone write simple code for this. i need using js and php. how can i write the logic. if you can then please write simple website code using html,js and php. thank you.
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<?php
header('Content-Type: application/json');

$input = json_decode(file_get_contents('php://input'), true);
$videoUrl = $input['url'];

if (filter_var($videoUrl, FILTER_VALIDATE_URL) === false) {
    echo json_encode(['success' => false, 'message' => 'Invalid URL']);
    exit();
}



$downloadLink = getFacebookVideoDownloadLink($videoUrl);

if ($downloadLink) {
    echo json_encode(['success' => true, 'download_url' => $downloadLink]);
} else {
    echo json_encode(['success' => false, 'message' => 'Failed to retrieve the video.']);
}

function getFacebookVideoDownloadLink($url) {
   
    return 'https://video-ams4-1.xx.fbcdn.net/o1/v/t2/f2/m69/';
}
?>```